This invention generally relates to intraluminal catheters, such as guiding catheters and fixed-wire balloon dilatation catheters used in percutaneous transluminal coronary angioplasty (PTCA).
In PTCA procedures, a guiding catheter having a preshaped distal tip is percutaneously introduced into the cardiovascular system of a patient and advanced therein until the preshaped distal tip of the guiding catheter is disposed within the aorta adjacent to the ostium of the desired coronary artery. The guiding catheter is twisted or torqued from the proximal end, which extends out of the patient, to turn the distal tip of the guiding catheter so that it can be guided into the desired coronary ostium. When utilizing a fixed-wire dilatation catheter in PTCA procedures, such as described and claimed in U.S. Pat. No. 4,582,181 (now U.S. Pat. No. Re. 33,166), the fixed-wire dilatation catheter is introduced into, and advanced through, the guiding catheter to the distal tip. Before the fixed-wire dilatation catheter is introduced into the guiding catheter, the distal tip of the dilatation catheter is usually manually shaped (curved) by the physician or one of the attendants. The fixed-wire dilatation catheter is advanced out the distal tip of the guiding catheter until the inflatable member on the distal extremity of the dilatation catheter extends across the lesion to be dilated. Once properly positioned across the lesion, the inflatable member is expanded to a predetermined size by inflation with radiopaque liquid at relatively high pressures (e.g., about 4-20 atmospheres) in order to dilate the stenosed region of the diseased artery. One or more inflations may be required to complete the dilatation of the stenosis. Dilatation of several stenoses in one patient can be performed with the same catheter. Upon the completion of the dilatations, the balloon is deflated so that the fixed-wire dilatation catheter can be removed from the dilated stenosis, and so that blood flow can resume through the dilated artery.
Further details of guiding catheters, fixed-wire dilatation catheters and other devices for angioplasty procedures can be found in U.S. Pat. No. Re. 33,166 (Samson); U.S. Pat. No. 4,439,185 (Lundquist); U.S. Pat. No. 4,468,224 (Enzmann et al.); U.S. Pat. No. 4,516,972 (Samson); U.S. Pat. No. 4,438,622 (Samson et al.); U.S. Pat. No. 4,554,929 (Samson et al.); U.S. Pat. No. 4,582,185 (Samson); U.S. Pat. No. 4,619,263 (Frisbie et al.); U.S. Pat. No. 4,638,805 (Powell); U.S. Pat. No. 4,641,654 (Samson et al.); U.S. Pat. No. 4,664,113 (Frisbie et al.); U.S. Pat. No. 4,748,986 (Morrison et al.); U.S. Pat. No. 4,771,778 (Mar); U.S. Pat. No. 4,793,350 (Mar et al.); U.S. Pat. No. 4,827,943 (Taylor et al.); U.S. Pat. No. 4,898,577 (Badger et al.); U.S. Pat. No. 4,966,163 (Kraus et al.); and U.S. Pat. No. 4,998,923 (Samson et al.), which are incorporated herein in their entirety by reference thereto.
Fixed-wire dilatation catheters for coronary angioplasty generally have an outer tubular member with an inflatable balloon on its distal portion which is capable of dilating a stenosis when the balloon is inflated to elevated pressures, and a shapable guiding member extending out through the distal end of the balloon which aids in directing the catheter to a desired branch artery where the stenosis to be dilated is located. The fixed-wire catheters usually have no inner tubular member and therefore usually have lower profiles, i.e. smaller transverse dimensions, than over-the-wire dilatation catheters having the same inflated balloon size. Moreover, because the fixed-wire catheters have the guidewire or guiding member fixed or at least restricted somewhat as to longitudinal movement, these catheters generally have greater pushability than over-the-wire type catheters of equivalent size. The lower profile and greater pushability of the fixed-wire dilatation catheters allows them to cross tighter lesions and to be advanced much deeper into a patient's coronary anatomy than the over-the-wire dilatation catheters of comparable sizes.
A major thrust in the development of materials and structure for intravascular catheters, such as balloon dilatation catheters, has been to reduce the profile or outer diameter of the catheter. The components of presently available dilatation catheters are usually made from homogeneous material, and the properties of available homogeneous materials suitable for catheter components have for the most part been pushed to the limit for these materials. In U.S. Pat. No. 4,981,478 (Evard et al.) composite catheter constructions are described which provide substantial improvements in catheter properties. However, notwithstanding the improvements made in properties of materials suitable for intravascular catheters, particularly fixed-wire dilatation catheters and guiding catheters for coronary use, a need remains for even greater improvements in property combinations which are not now available. The composite catheter construction of the present invention provides substantial improvements in properties and substantial reductions in transverse dimensions, and therefore responds to the aforesaid needs.